A spray beam is arranged in the proximity of a printing press roller for spraying fountain solution thereon. This fountain solution is needed for obtaining the intended printing function in the printing press, as is well known in the art. (Other liquids than fountain solution could alternatively be sprayed.)
It is also well known in the art that at the high speed rotation of the different rollers in the printing press, it is difficult to obviate the formation of a mist of printing ink and other matters in and around the press. The printing ink also causes certain problems in the operation of the press.
The printing ink mist causes clogging of the spray nozzles of the spray beam, so that their intended spray function gradually deteriorates and the spray pattern of the spray beam is changed.
A prior attempt to solve the problem with clogged spray nozzles in a special situation is revealed in WO 0187603, where an air stream is caused to flow towards the printing press roller in the spray casing covering the area between the spray beam and the roller.